The test currently crashes as:
AddressSanitizer: CHECK failed: asan_poisoning.cpp:38 "((AddrIsAlignedByGranularity(addr))) != (0)"
Main stack address/size don't have to be aligned on asan shadow granularity.
Align stack bottom.
Reviewed By: melver, vitalybuka
Differential Revision: https://reviews.llvm.org/D145799